/*
 * jcapimin.c
 *
 * Copyright (C) 1994-1995, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains application interface code for the compression half
 * of the JPEG library.  These are the "minimum" API routines that may be
 * needed in either the normal full-compression case or the transcoding-only
 * case.
 *
 * Most of the routines intended to be called directly by an application
 * are in this file or in jcapistd.c.  But also see jcparam.c for
 * parameter-setup helper routines, jcomapi.c for routines shared by
 * compression and decompression, and jctrans.c for the transcoding case.
 */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"


/*
 * Initialization of a JPEG compression object.
 * The error manager must already be set up (in case memory manager fails).
 */

GLOBAL void jpeg_create_compress(j_compress_ptr cinfo)
{
	int             i;

	/* For debugging purposes, zero the whole master structure.
	 * But error manager pointer is already there, so save and restore it.
	 */
	{
		struct jpeg_error_mgr *err = cinfo->err;
		MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));

		cinfo->err = err;
	}
	cinfo->is_decompressor = FALSE;

	/* Initialize a memory manager instance for this object */
	jinit_memory_mgr((j_common_ptr) cinfo);

	/* Zero out pointers to permanent structures. */
	cinfo->progress = NULL;
	cinfo->dest = NULL;

	cinfo->comp_info = NULL;

	for(i = 0; i < NUM_QUANT_TBLS; i++)
		cinfo->quant_tbl_ptrs[i] = NULL;

	for(i = 0; i < NUM_HUFF_TBLS; i++)
	{
		cinfo->dc_huff_tbl_ptrs[i] = NULL;
		cinfo->ac_huff_tbl_ptrs[i] = NULL;
	}

	cinfo->input_gamma = 1.0;	/* in case application forgets */

	/* OK, I'm ready */
	cinfo->global_state = CSTATE_START;
}


/*
 * Destruction of a JPEG compression object
 */

GLOBAL void jpeg_destroy_compress(j_compress_ptr cinfo)
{
	jpeg_destroy((j_common_ptr) cinfo);	/* use common routine */
}


/*
 * Abort processing of a JPEG compression operation,
 * but don't destroy the object itself.
 */

GLOBAL void jpeg_abort_compress(j_compress_ptr cinfo)
{
	jpeg_abort((j_common_ptr) cinfo);	/* use common routine */
}


/*
 * Forcibly suppress or un-suppress all quantization and Huffman tables.
 * Marks all currently defined tables as already written (if suppress)
 * or not written (if !suppress).  This will control whether they get emitted
 * by a subsequent jpeg_start_compress call.
 *
 * This routine is exported for use by applications that want to produce
 * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
 * since it is called by jpeg_start_compress, we put it here --- otherwise
 * jcparam.o would be linked whether the application used it or not.
 */

GLOBAL void jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress)
{
	int             i;
	JQUANT_TBL     *qtbl;
	JHUFF_TBL      *htbl;

	for(i = 0; i < NUM_QUANT_TBLS; i++)
	{
		if((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
			qtbl->sent_table = suppress;
	}

	for(i = 0; i < NUM_HUFF_TBLS; i++)
	{
		if((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
			htbl->sent_table = suppress;
		if((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
			htbl->sent_table = suppress;
	}
}


/*
 * Finish JPEG compression.
 *
 * If a multipass operating mode was selected, this may do a great deal of
 * work including most of the actual output.
 */

GLOBAL void jpeg_finish_compress(j_compress_ptr cinfo)
{
	JDIMENSION      iMCU_row;

	if(cinfo->global_state == CSTATE_SCANNING || cinfo->global_state == CSTATE_RAW_OK)
	{
		/* Terminate first pass */
		if(cinfo->next_scanline < cinfo->image_height)
			ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
		(*cinfo->master->finish_pass) (cinfo);
	}
	else if(cinfo->global_state != CSTATE_WRCOEFS)
		ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
	/* Perform any remaining passes */
	while(!cinfo->master->is_last_pass)
	{
		(*cinfo->master->prepare_for_pass) (cinfo);
		for(iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++)
		{
			if(cinfo->progress != NULL)
			{
				cinfo->progress->pass_counter = (long)iMCU_row;
				cinfo->progress->pass_limit = (long)cinfo->total_iMCU_rows;
				(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
			}
			/* We bypass the main controller and invoke coef controller directly;
			 * all work is being done from the coefficient buffer.
			 */
			if(!(*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
				ERREXIT(cinfo, JERR_CANT_SUSPEND);
		}
		(*cinfo->master->finish_pass) (cinfo);
	}
	/* Write EOI, do final cleanup */
	(*cinfo->marker->write_file_trailer) (cinfo);
	(*cinfo->dest->term_destination) (cinfo);
	/* We can use jpeg_abort to release memory and reset global_state */
	jpeg_abort((j_common_ptr) cinfo);
}


/*
 * Write a special marker.
 * This is only recommended for writing COM or APPn markers.
 * Must be called after jpeg_start_compress() and before
 * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
 */

GLOBAL void jpeg_write_marker(j_compress_ptr cinfo, int marker, const JOCTET * dataptr, unsigned int datalen)
{
	if(cinfo->next_scanline != 0 ||
	   (cinfo->global_state != CSTATE_SCANNING && cinfo->global_state != CSTATE_RAW_OK && cinfo->global_state != CSTATE_WRCOEFS))
		ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

	(*cinfo->marker->write_any_marker) (cinfo, marker, dataptr, datalen);
}


/*
 * Alternate compression function: just write an abbreviated table file.
 * Before calling this, all parameters and a data destination must be set up.
 *
 * To produce a pair of files containing abbreviated tables and abbreviated
 * image data, one would proceed as follows:
 *
 *		initialize JPEG object
 *		set JPEG parameters
 *		set destination to table file
 *		jpeg_write_tables(cinfo);
 *		set destination to image file
 *		jpeg_start_compress(cinfo, FALSE);
 *		write data...
 *		jpeg_finish_compress(cinfo);
 *
 * jpeg_write_tables has the side effect of marking all tables written
 * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
 * will not re-emit the tables unless it is passed write_all_tables=TRUE.
 */

GLOBAL void jpeg_write_tables(j_compress_ptr cinfo)
{
	if(cinfo->global_state != CSTATE_START)
		ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

	/* (Re)initialize error mgr and destination modules */
	(*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
	(*cinfo->dest->init_destination) (cinfo);
	/* Initialize the marker writer ... bit of a crock to do it here. */
	jinit_marker_writer(cinfo);
	/* Write them tables! */
	(*cinfo->marker->write_tables_only) (cinfo);
	/* And clean up. */
	(*cinfo->dest->term_destination) (cinfo);
	/* We can use jpeg_abort to release memory. */
	jpeg_abort((j_common_ptr) cinfo);
}
